1. Field of the Invention
The present invention relates to a magnetic head suspension for supporting a magnetic head slider that reads and/or writes data from and to a recording medium such as a hard disk drive.
2. Related Art
Increase in capacity of a magnetic disk device requires improvement in accuracy for positioning a magnetic head slider on a target track. In this regard, there has been proposed a magnetic head suspension that enables coarse motion of a magnetic head slider in a seek direction by a main actuator such as a voice coil motor as well as micro motion of the magnetic head slider in the seek direction by piezoelectric elements functioning as a sub actuator (for example, see Japanese Unexamined Patent Application Publications No. H02-227886, No. H11-016311, and No. 2001-307442).
The magnetic head suspension including the piezoelectric elements as described above needs to be provided with a less rigid region in a supporting part that is swung directly or indirectly by the main actuator such as a voice coil motor in order to realize the micro motion of the magnetic head slider by the piezoelectric elements.
More specifically, the magnetic head suspension provided with the piezoelectric elements includes a load bending part that generates a load for pressing the magnetic head slider toward a disk surface, a load beam part that transmits the load to the magnetic head slider, the supporting part that supports the load beam part via the load bending part and is swung about a swing center directly or indirectly by the main actuator, a flexure part that is supported by the load beam part and the supporting part while supporting the magnetic head slider, and the piezoelectric elements that are attached to the supporting part.
The supporting part is provided with a proximal end region that is connected directly or indirectly to the main actuator, a distal end region to which the load bending part is connected, and the less rigid region that connects the proximal end region and the distal end region with each other. The micro motion of the magnetic head slider is realized by elastic deformation of the less rigid region in response to expansion and contraction motion of the piezoelectric elements.
In a case where the rigidity is reduced in the less rigid region, the magnetic head slider can be more easily displaced in the seek direction (in a radial direction in parallel with the disk surface) by the piezoelectric elements. On the other hand, such reduction in rigidity of the less rigid region increases a stress applied to the piezoelectric elements upon reception of an impact force by a magnetic disk device that is provided with the magnetic head suspension, and also lowers the resonance frequency of the magnetic head suspension.